package PVE::Diskmanage;

use strict;
use warnings;

use PVE::ProcFSTools;
use Data::Dumper;
use Cwd qw(abs_path);
use Fcntl ':mode';
use File::Basename;
use File::stat;
use JSON;

use PVE::Tools
    qw(extract_param run_command file_get_contents file_read_firstline dir_glob_regex dir_glob_foreach trim);

my $SMARTCTL = "/usr/sbin/smartctl";
my $ZPOOL = "/sbin/zpool";
my $SGDISK = "/sbin/sgdisk";
my $PVS = "/sbin/pvs";
my $LVS = "/sbin/lvs";
my $LSBLK = "/bin/lsblk";

my sub strip_dev : prototype($) {
    my ($devpath) = @_;
    $devpath =~ s|^/dev/||;
    return $devpath;
}

sub check_bin {
    my ($path) = @_;
    return -x $path;
}

sub verify_blockdev_path {
    my ($rel_path) = @_;

    die "missing path" if !$rel_path;
    my $path = abs_path($rel_path);
    die "failed to get absolute path to $rel_path\n" if !$path;

    die "got unusual device path '$path'\n" if $path !~ m|^/dev/(.*)$|;

    $path = "/dev/$1"; # untaint

    assert_blockdev($path);

    return $path;
}

sub assert_blockdev {
    my ($dev, $noerr) = @_;

    if ($dev !~ m|^/dev/| || !(-b $dev)) {
        return if $noerr;
        die "not a valid block device\n";
    }

    return 1;
}

sub init_disk {
    my ($disk, $uuid) = @_;

    assert_blockdev($disk);

    # we should already have checked these in the api call, but we check again for safety
    die "$disk is a partition\n" if is_partition($disk);
    die "disk $disk is already in use\n" if disk_is_used($disk);

    my $id = $uuid || 'R';
    run_command([$SGDISK, $disk, '-U', $id]);
    return 1;
}

sub disk_is_used {
    my ($disk) = @_;

    my $dev = $disk;
    $dev =~ s|^/dev/||;

    my $disklist = get_disks($dev, 1, 1);

    die "'$disk' is not a valid local disk\n" if !defined($disklist->{$dev});
    return 1 if $disklist->{$dev}->{used};

    return 0;
}

sub get_smart_data {
    my ($disk, $healthonly) = @_;

    assert_blockdev($disk);
    my $smartdata = {};
    my $type;

    my $cmd = [$SMARTCTL, '-H'];
    push @$cmd, '-A', '-f', 'brief' if !$healthonly;
    push @$cmd, $disk;

    my $returncode = eval {
        run_command(
            $cmd,
            noerr => 1,
            outfunc => sub {
                my ($line) = @_;

                # ATA SMART attributes, e.g.:
                # ID# ATTRIBUTE_NAME          FLAGS    VALUE WORST THRESH FAIL RAW_VALUE
                #   1 Raw_Read_Error_Rate     POSR-K   100   100   000    -    0
                #
                # SAS and NVME disks, e.g.:
                # Data Units Written:                 5,584,952 [2.85 TB]
                # Accumulated start-stop cycles:  34

                if (
                    defined($type)
                    && $type eq 'ata'
                    && $line =~
                    m/^([ \d]{2}\d)\s+(\S+)\s+(\S{6})\s+(\d+)\s+(\d+)\s+(\S+)\s+(\S+)\s+(.*)$/
                ) {
                    my $entry = {};

                    $entry->{name} = $2 if defined $2;
                    $entry->{flags} = $3 if defined $3;
                    # the +0 makes a number out of the strings
                    # FIXME: 'value' is depreacated by 'normalized'; remove with PVE 7.0
                    $entry->{value} = $4 + 0 if defined $4;
                    $entry->{normalized} = $4 + 0 if defined $4;
                    $entry->{worst} = $5 + 0 if defined $5;
                    # some disks report the default threshold as --- instead of 000
                    if (defined($6) && $6 eq '---') {
                        $entry->{threshold} = 0;
                    } else {
                        $entry->{threshold} = $6 + 0 if defined $6;
                    }
                    $entry->{fail} = $7 if defined $7;
                    $entry->{raw} = $8 if defined $8;
                    $entry->{id} = $1 if defined $1;
                    push @{ $smartdata->{attributes} }, $entry;
                } elsif ($line =~ m/(?:Health Status|self\-assessment test result): (.*)$/) {
                    $smartdata->{health} = $1;
                } elsif ($line =~ m/Vendor Specific SMART Attributes with Thresholds:/) {
                    $type = 'ata';
                    delete $smartdata->{text};
                } elsif ($line =~ m/=== START OF (READ )?SMART DATA SECTION ===/) {
                    $type = 'text';
                } elsif (defined($type) && $type eq 'text') {
                    $smartdata->{text} = '' if !defined $smartdata->{text};
                    $smartdata->{text} .= "$line\n";
                    # extract wearout from nvme/sas text, allow for decimal values
                    if ($line =~
                        m/Percentage Used(?: endurance indicator)?:\s*(\d+(?:\.\d+)?)\%/i
                    ) {
                        $smartdata->{wearout} = 100 - $1;
                    }
                } elsif ($line =~ m/SMART Disabled/) {
                    $smartdata->{health} = "SMART Disabled";
                }
            },
        );
    };
    my $err = $@;

    # bit 0 and 1 mark a fatal error, other bits are for disk status -> ignore (see man 8 smartctl)
    if ((defined($returncode) && ($returncode & 0b00000011)) || $err) {
        die "Error getting S.M.A.R.T. data: Exit code: $returncode\n";
    }

    $smartdata->{type} = $type;

    return $smartdata;
}

sub get_lsblk_info {
    my $cmd = [$LSBLK, '--json', '-o', 'path,parttype,fstype'];
    my $output = "";
    eval {
        run_command($cmd, outfunc => sub { $output .= "$_[0]\n"; });
    };
    warn "$@\n" if $@;
    return {} if $output eq '';

    my $parsed = eval { decode_json($output) } // {};
    warn "$@\n" if $@;
    my $list = $parsed->{blockdevices} // [];

    return {
        map {
            $_->{path} => {
                parttype => $_->{parttype},
                fstype => $_->{fstype},
            }
        } @{$list}
    };
}

my sub get_devices_by_partuuid {
    my ($lsblk_info, $uuids, $res) = @_;

    $res = {} if !defined($res);

    foreach my $dev (sort keys %{$lsblk_info}) {
        my $uuid = $lsblk_info->{$dev}->{parttype};
        next if !defined($uuid) || !defined($uuids->{$uuid});
        $res->{$dev} = $uuids->{$uuid};
    }

    return $res;
}

sub get_zfs_devices {
    my ($lsblk_info) = @_;
    my $res = {};

    return {} if !check_bin($ZPOOL);

    # use zpool and parttype uuid, because log and cache do not have zfs type uuid
    eval {
        run_command(
            [$ZPOOL, 'list', '-HPLv'],
            outfunc => sub {
                my ($line) = @_;
                if ($line =~ m|^\t([^\t]+)\t|) {
                    $res->{$1} = 1;
                }
            },
        );
    };

    # only warn here, because maybe zfs tools are not installed
    warn "$@\n" if $@;

    my $uuids = {
        "6a898cc3-1dd2-11b2-99a6-080020736631" => 1, # apple
        "516e7cba-6ecf-11d6-8ff8-00022d09712b" => 1, # bsd
    };

    $res = get_devices_by_partuuid($lsblk_info, $uuids, $res);

    return $res;
}

sub get_lvm_devices {
    my ($lsblk_info) = @_;
    my $res = {};
    eval {
        run_command(
            [$PVS, '--noheadings', '--readonly', '-o', 'pv_name'],
            outfunc => sub {
                my ($line) = @_;
                $line = trim($line);
                if ($line =~ m|^/dev/|) {
                    $res->{$line} = 1;
                }
            },
        );
    };

    # if something goes wrong, we do not want to give up, but indicate an error has occurred
    warn "$@\n" if $@;

    my $uuids = {
        "e6d6d379-f507-44c2-a23c-238f2a3df928" => 1,
    };

    $res = get_devices_by_partuuid($lsblk_info, $uuids, $res);

    return $res;
}

sub get_ceph_journals {
    my ($lsblk_info) = @_;
    my $res = {};

    my $uuids = {
        '45b0969e-9b03-4f30-b4c6-b4b80ceff106' => 1, # journal
        '30cd0809-c2b2-499c-8879-2d6b78529876' => 2, # db
        '5ce17fce-4087-4169-b7ff-056cc58473f9' => 3, # wal
        'cafecafe-9b03-4f30-b4c6-b4b80ceff106' => 4, # block
    };

    $res = get_devices_by_partuuid($lsblk_info, $uuids, $res);

    return $res;
}

# reads the lv_tags and matches them with the devices
sub get_ceph_volume_infos {
    my $result = {};

    my $cmd = [
        $LVS,
        '-S',
        'lv_name=~^osd-',
        '-o',
        'devices,lv_name,lv_tags',
        '--noheadings',
        '--readonly',
        '--separator',
        ';',
    ];

    run_command(
        $cmd,
        outfunc => sub {
            my $line = shift;
            $line =~ s/(?:^\s+)|(?:\s+$)//g; # trim whitespaces

            my $fields = [split(';', $line)];

            # lvs syntax is /dev/sdX(Y) where Y is the start (which we do not need)
            my ($dev) = $fields->[0] =~ m|^(/dev/[a-z]+[^(]*)|;
            if ($fields->[1] =~ m|^osd-([^-]+)-|) {
                my $type = $1;
                # $result autovivification is wanted, to not creating empty hashes
                if (
                    ($type eq 'block' || $type eq 'data')
                    && $fields->[2] =~ m/ceph.osd_id=([^,]+)/
                ) {
                    $result->{$dev}->{osdid} = $1;
                    if (!defined($result->{$dev}->{'osdid-list'})) {
                        $result->{$dev}->{'osdid-list'} = [];
                    }
                    push($result->{$dev}->{'osdid-list'}->@*, $1);
                    $result->{$dev}->{bluestore} = ($type eq 'block');
                    if ($fields->[2] =~ m/ceph\.encrypted=1/) {
                        $result->{$dev}->{encrypted} = 1;
                    }
                } else {
                    # undef++ becomes '1' (see `perldoc perlop`: Auto-increment)
                    $result->{$dev}->{$type}++;
                }
            }
        },
    );

    return $result;
}

sub get_udev_info {
    my ($dev) = @_;

    my $info = "";
    my $data = {};
    eval {
        run_command(
            ['udevadm', 'info', '-p', $dev, '--query', 'all'],
            outfunc => sub {
                my ($line) = @_;
                $info .= "$line\n";
            },
        );
    };
    warn $@ if $@;
    return if !$info;

    return if $info !~ m/^E: DEVTYPE=(disk|partition)$/m;
    return if $info =~ m/^E: ID_CDROM/m;

    # we use this, because some disks are not simply in /dev e.g. /dev/cciss/c0d0
    if ($info =~ m/^E: DEVNAME=(\S+)$/m) {
        $data->{devpath} = $1;
    }
    return if !defined($data->{devpath});

    $data->{serial} = 'unknown';
    $data->{serial} = $1 if $info =~ m/^E: ID_SERIAL_SHORT=\s*(\S+)$/m;

    $data->{gpt} = $info =~ m/^E: ID_PART_TABLE_TYPE=gpt$/m ? 1 : 0;

    $data->{rpm} = -1;
    $data->{rpm} = $1 if $info =~ m/^E: ID_ATA_ROTATION_RATE_RPM=(\d+)$/m; # detects SSD implicit

    $data->{usb} = 1 if $info =~ m/^E: ID_BUS=usb$/m;

    $data->{model} = $1 if $info =~ m/^E: ID_MODEL=(.+)$/m;

    $data->{wwn} = 'unknown';
    $data->{wwn} = $1 if $info =~ m/^E: ID_WWN=(.*)$/m;

    if ($info =~ m/^E: DEVLINKS=(.+)$/m) {
        my @devlinks = grep(m#^/dev/disk/by-id/(ata|scsi|nvme(?!-eui))#, split(/ /, $1));
        $data->{by_id_link} = $devlinks[0] if defined($devlinks[0]);
    }

    return $data;
}

sub get_sysdir_size {
    my ($sysdir) = @_;

    my $size = file_read_firstline("$sysdir/size");
    return if !$size;

    # linux always considers sectors to be 512 bytes, independently of real block size
    return $size * 512;
}

sub get_sysdir_info {
    my ($sysdir) = @_;

    return if !-d "$sysdir/device";

    my $data = {};

    $data->{size} = get_sysdir_size($sysdir) or return;

    # dir/queue/rotational should be 1 for hdd, 0 for ssd
    $data->{rotational} = file_read_firstline("$sysdir/queue/rotational") // -1;

    $data->{vendor} = file_read_firstline("$sysdir/device/vendor") || 'unknown';
    $data->{model} = file_read_firstline("$sysdir/device/model") || 'unknown';

    return $data;
}

sub get_wear_leveling_info {
    my ($smartdata) = @_;
    my $attributes = $smartdata->{attributes};

    if (defined($smartdata->{wearout})) {
        return $smartdata->{wearout};
    }

    my $wearout;

    # Common register names that represent percentage values of potential failure indicators used
    # in drivedb.h of smartmontool's. Order matters, as some drives may have multiple definitions
    my @wearoutregisters = (
        "Media_Wearout_Indicator",
        "SSD_Life_Left",
        "Wear_Leveling_Count",
        "Perc_Write\/Erase_Ct_BC",
        "Perc_Rated_Life_Remain",
        "Remaining_Lifetime_Perc",
        "Percent_Lifetime_Remain",
        "Lifetime_Left",
        "PCT_Life_Remaining",
        "Lifetime_Remaining",
        "Percent_Life_Remaining",
        "Percent_Lifetime_Used",
        "Perc_Rated_Life_Used",
    );

    # Search for S.M.A.R.T. attributes for known register
    foreach my $register (@wearoutregisters) {
        last if defined $wearout;
        foreach my $attr (@$attributes) {
            next if $attr->{name} !~ m/$register/;
            $wearout = $attr->{value};
            last;
        }
    }

    return $wearout;
}

sub dir_is_empty {
    my ($dir) = @_;

    my $dh = IO::Dir->new($dir);
    return 1 if !$dh;

    while (defined(my $tmp = $dh->read)) {
        next if $tmp eq '.' || $tmp eq '..';
        $dh->close;
        return 0;
    }
    $dh->close;
    return 1;
}

sub is_iscsi {
    my ($sysdir) = @_;

    if (-l $sysdir && readlink($sysdir) =~ m|host[^/]*/session[^/]*|) {
        return 1;
    }

    return 0;
}

my sub is_ssdlike {
    my ($type) = @_;
    return $type eq 'ssd' || $type eq 'nvme';
}

sub mounted_blockdevs {
    my $mounted = {};

    my $mounts = PVE::ProcFSTools::parse_proc_mounts();

    foreach my $mount (@$mounts) {
        next if $mount->[0] !~ m|^/dev/|;
        $mounted->{ abs_path($mount->[0]) } = $mount->[1];
    }

    return $mounted;
}

# returns hashmap of abs mount path -> first part of /proc/mounts (what)
sub mounted_paths {
    my $mounted = {};

    my $mounts = PVE::ProcFSTools::parse_proc_mounts();

    foreach my $mount (@$mounts) {
        $mounted->{ abs_path($mount->[1]) } = $mount->[0];
    }

    return $mounted;
}

sub get_disks {
    my ($disks, $nosmart, $include_partitions) = @_;
    my $disklist = {};

    my $mounted = mounted_blockdevs();

    my $lsblk_info = get_lsblk_info();

    my $journalhash = get_ceph_journals($lsblk_info);
    my $ceph_volume_infos = get_ceph_volume_infos();

    my $zfshash = get_zfs_devices($lsblk_info);

    my $lvmhash = get_lvm_devices($lsblk_info);

    my $disk_regex = ".*";
    if (defined($disks)) {
        if (!ref($disks)) {
            $disks = [$disks];
        } elsif (ref($disks) ne 'ARRAY') {
            die "disks is not a string or array reference\n";
        }
        # we get cciss/c0d0 but need cciss!c0d0
        $_ =~ s|cciss/|cciss!| for @$disks;

        if ($include_partitions) {
            # Proper blockdevice is needed for the regex, use parent for partitions.
            for my $disk ($disks->@*) {
                next if !is_partition("/dev/$disk");
                $disk = strip_dev(get_blockdev("/dev/$disk"));
            }
        }

        $disk_regex = "(?:" . join('|', @$disks) . ")";
    }

    dir_glob_foreach(
        '/sys/block',
        $disk_regex,
        sub {
            my ($dev) = @_;
            # whitelisting following devices
            # - hdX         ide block device
            # - sdX         scsi/sata block device
            # - vdX         virtIO block device
            # - xvdX:       xen virtual block device
            # - nvmeXnY:    nvme devices
            # - cciss!cXnY  cciss devices
            return
                if $dev !~ m/^(h|s|x?v)d[a-z]+$/
                && $dev !~ m/^nvme\d+n\d+$/
                && $dev !~ m/^cciss\!c\d+d\d+$/;

            my $data = get_udev_info("/sys/block/$dev") // return;
            my $devpath = $data->{devpath};

            my $sysdir = "/sys/block/$dev";

            # we do not want iscsi devices
            return if is_iscsi($sysdir);

            my $sysdata = get_sysdir_info($sysdir);
            return if !defined($sysdata);

            my $type = 'unknown';

            if ($sysdata->{rotational} == 0) {
                $type = 'ssd';
                $type = 'nvme' if $dev =~ m/^nvme\d+n\d+$/;
                $data->{rpm} = 0;
            } elsif ($sysdata->{rotational} == 1) {
                if ($data->{rpm} != -1) {
                    $type = 'hdd';
                } elsif ($data->{usb}) {
                    $type = 'usb';
                    $data->{rpm} = 0;
                }
            }

            my ($health, $wearout) = ('UNKNOWN', 'N/A');
            if (!$nosmart) {
                eval {
                    my $smartdata = get_smart_data($devpath, !is_ssdlike($type));
                    $health = $smartdata->{health} if $smartdata->{health};

                    if (is_ssdlike($type)) { # if we have an ssd we try to get the wearout indicator
                        my $wear_level = get_wear_leveling_info($smartdata);
                        $wearout = $wear_level if defined($wear_level);
                    }
                };
            }

            # we replaced cciss/ with cciss! above, but in the result we need cciss/ again because the
            # caller might want to check the result again with the original parameter
            if ($dev =~ m|^cciss!|) {
                $dev =~ s|^cciss!|cciss/|;
            }

            $disklist->{$dev} = {
                vendor => $sysdata->{vendor},
                model => $data->{model} || $sysdata->{model},
                size => $sysdata->{size},
                serial => $data->{serial},
                gpt => $data->{gpt},
                rpm => $data->{rpm},
                type => $type,
                wwn => $data->{wwn},
                health => $health,
                devpath => $devpath,
                wearout => $wearout,
            };
            $disklist->{$dev}->{mounted} = 1 if exists $mounted->{$devpath};

            my $by_id_link = $data->{by_id_link};
            $disklist->{$dev}->{by_id_link} = $by_id_link if defined($by_id_link);

            my ($osdid, $bluestore, $osdencrypted) = (-1, 0, 0);
            my $osdid_list;
            my ($journal_count, $db_count, $wal_count) = (0, 0, 0);

            my $partpath = $devpath;
            # remove trailing part to get the partition base path, e.g. /dev/cciss/c0d0 -> /dev/cciss
            $partpath =~ s/\/[^\/]+$//;

            my $determine_usage = sub {
                my ($devpath, $sysdir, $is_partition) = @_;

                return 'LVM' if $lvmhash->{$devpath};
                return 'ZFS' if $zfshash->{$devpath};

                my $info = $lsblk_info->{$devpath} // {};

                if (defined(my $parttype = $info->{parttype})) {
                    return 'BIOS boot' if $parttype eq '21686148-6449-6e6f-744e-656564454649';
                    return 'EFI' if $parttype eq 'c12a7328-f81f-11d2-ba4b-00a0c93ec93b';
                    return 'ZFS reserved'
                        if $parttype eq '6a945a3b-1dd2-11b2-99a6-080020736631';
                }

                return "$info->{fstype}" if defined($info->{fstype});
                return 'mounted' if $mounted->{$devpath};

                return if !$is_partition;

                # for devices, this check is done explicitly later
                return 'Device Mapper' if !dir_is_empty("$sysdir/holders");

                return; # unused partition
            };

            my $collect_ceph_info = sub {
                my ($devpath) = @_;

                my $ceph_volume = $ceph_volume_infos->{$devpath} or return;
                $journal_count += $ceph_volume->{journal} // 0;
                $db_count += $ceph_volume->{db} // 0;
                $wal_count += $ceph_volume->{wal} // 0;
                if (defined($ceph_volume->{osdid})) {
                    $osdid = $ceph_volume->{osdid};
                    $osdid_list = $ceph_volume->{'osdid-list'};
                    $bluestore = 1 if $ceph_volume->{bluestore};
                    $osdencrypted = 1 if $ceph_volume->{encrypted};
                }

                my $result = { %{$ceph_volume} };
                $result->{journals} = delete $result->{journal} if $result->{journal};
                return $result;
            };

            my $partitions = {};
            dir_glob_foreach(
                "$sysdir",
                "$dev.+",
                sub {
                    my ($part) = @_;

                    $partitions->{$part} = $collect_ceph_info->("$partpath/$part");
                    my $lvm_based_osd = defined($partitions->{$part});

                    $partitions->{$part}->{devpath} = "$partpath/$part";
                    $partitions->{$part}->{parent} = "$devpath";
                    $partitions->{$part}->{mounted} = 1 if exists $mounted->{"$partpath/$part"};
                    $partitions->{$part}->{gpt} = $data->{gpt};
                    $partitions->{$part}->{type} = 'partition';
                    $partitions->{$part}->{size} = get_sysdir_size("$sysdir/$part") // 0;
                    $partitions->{$part}->{used} =
                        $determine_usage->("$partpath/$part", "$sysdir/$part", 1);
                    $partitions->{$part}->{osdid} //= -1;
                    $partitions->{$part}->{'osdid-list'} //= undef;

                    # avoid counting twice (e.g. partition with the LVM for the DB OSD is in $journalhash)
                    return if $lvm_based_osd;

                    # Legacy handling for non-LVM based OSDs
                    if (my $mp = $mounted->{"$partpath/$part"}) {
                        if ($mp =~ m|^/var/lib/ceph/osd/ceph-(\d+)$|) {
                            $osdid = $1;
                            $partitions->{$part}->{osdid} = $osdid;
                            $osdid_list = [$1]; # assuming only one OSD per disk
                            $partitions->{$part}->{'osdid-list'} = $osdid_list;
                        }
                    }

                    if (my $journal_part = $journalhash->{"$partpath/$part"}) {
                        $journal_count++ if $journal_part == 1;
                        $db_count++ if $journal_part == 2;
                        $wal_count++ if $journal_part == 3;
                        $bluestore = 1 if $journal_part == 4;

                        $partitions->{$part}->{journals} = 1 if $journal_part == 1;
                        $partitions->{$part}->{db} = 1 if $journal_part == 2;
                        $partitions->{$part}->{wal} = 1 if $journal_part == 3;
                        $partitions->{$part}->{bluestore} = 1 if $journal_part == 4;
                    }
                },
            );

            my $used = $determine_usage->($devpath, $sysdir, 0);
            if (!$include_partitions) {
                foreach my $part (sort keys %{$partitions}) {
                    $used //= $partitions->{$part}->{used};
                }
            } else {
                # fstype might be set even if there are partitions, but showing that is confusing
                $used = 'partitions' if scalar(keys %{$partitions});
            }
            $used //= 'partitions' if scalar(keys %{$partitions});
            # multipath, software raid, etc.
            # this check comes in last, to show more specific info
            # if we have it
            $used //= 'Device Mapper' if !dir_is_empty("$sysdir/holders");

            $disklist->{$dev}->{used} = $used if $used;

            $collect_ceph_info->($devpath);

            $disklist->{$dev}->{osdid} = $osdid;
            $disklist->{$dev}->{'osdid-list'} = $osdid_list;
            $disklist->{$dev}->{journals} = $journal_count if $journal_count;
            $disklist->{$dev}->{bluestore} = $bluestore if $osdid != -1;
            $disklist->{$dev}->{osdencrypted} = $osdencrypted if $osdid != -1;
            $disklist->{$dev}->{db} = $db_count if $db_count;
            $disklist->{$dev}->{wal} = $wal_count if $wal_count;

            if ($include_partitions) {
                $disklist->{$_} = $partitions->{$_} for keys %{$partitions};
            }
        },
    );

    return $disklist;
}

sub get_partnum {
    my ($part_path) = @_;

    my $st = stat($part_path);

    die "error detecting block device '$part_path'\n"
        if !$st || !$st->mode || !S_ISBLK($st->mode) || !$st->rdev;

    my $major = PVE::Tools::dev_t_major($st->rdev);
    my $minor = PVE::Tools::dev_t_minor($st->rdev);
    my $partnum_path = "/sys/dev/block/$major:$minor/";

    my $partnum = file_read_firstline("${partnum_path}partition");
    die "Partition does not exist\n" if !defined($partnum);
    die "Failed to get partition number\n" if $partnum !~ m/(\d+)/; # untaint
    $partnum = $1;
    die "Partition number $partnum is invalid\n" if $partnum > 128;

    return $partnum;
}

sub get_blockdev {
    my ($part_path) = @_;

    my ($dev, $block_dev);
    if ($part_path =~ m|^/dev/(.*)$|) {
        $dev = $1;
        my $link = readlink "/sys/class/block/$dev";
        $block_dev = $1 if $link =~ m|([^/]*)/$dev$|;
    }

    die "Can't parse parent device\n" if !defined($block_dev);
    die "No valid block device\n" if index($dev, $block_dev) == -1;

    $block_dev = "/dev/$block_dev";
    die "Block device does not exists\n" if !(-b $block_dev);

    return $block_dev;
}

sub is_partition {
    my ($dev_path) = @_;

    return defined(eval { get_partnum($dev_path) });
}

sub locked_disk_action {
    my ($sub) = @_;
    my $res = PVE::Tools::lock_file('/run/lock/pve-diskmanage.lck', undef, $sub);
    die $@ if $@;
    return $res;
}

sub assert_disk_unused {
    my ($dev) = @_;
    die "device '$dev' is already in use\n" if disk_is_used($dev);
    return;
}

sub append_partition {
    my ($dev, $size) = @_;

    my $devname = $dev;
    $devname =~ s|^/dev/||;

    my $newpartid = 1;
    dir_glob_foreach(
        "/sys/block/$devname",
        qr/\Q$devname\E.*?(\d+)/,
        sub {
            my ($part, $partid) = @_;

            if ($partid >= $newpartid) {
                $newpartid = $partid + 1;
            }
        },
    );

    $size = PVE::Tools::convert_size($size, 'b' => 'mb');

    run_command(
        [$SGDISK, '-n', "$newpartid:0:+${size}M", $dev],
        errmsg => "error creating partition '$newpartid' on '$dev'",
    );

    my $partition;

    # loop again to detect the real partition device which does not always follow
    # a strict $devname$partition scheme like /dev/nvme0n1 -> /dev/nvme0n1p1
    dir_glob_foreach(
        "/sys/block/$devname",
        qr/\Q$devname\E.*$newpartid/,
        sub {
            my ($part) = @_;

            $partition = "/dev/$part";
        },
    );

    return $partition;
}

# Check if a disk or any of its partitions has a holder.
# Can also be called with a partition.
# Expected to be called with a result of verify_blockdev_path().
sub has_holder {
    my ($devpath) = @_;

    my $dev = strip_dev($devpath);

    return $devpath if !dir_is_empty("/sys/class/block/${dev}/holders");

    my $found;
    dir_glob_foreach(
        "/sys/block/${dev}",
        "${dev}.+",
        sub {
            my ($part) = @_;
            $found = "/dev/${part}" if !dir_is_empty("/sys/class/block/${part}/holders");
        },
    );

    return $found;
}

# Basic check if a disk or any of its partitions is mounted.
# Can also be called with a partition.
# Expected to be called with a result of verify_blockdev_path().
sub is_mounted {
    my ($devpath) = @_;

    my $mounted = mounted_blockdevs();

    return $devpath if $mounted->{$devpath};

    my $dev = strip_dev($devpath);

    my $found;
    dir_glob_foreach(
        "/sys/block/${dev}",
        "${dev}.+",
        sub {
            my ($part) = @_;
            my $partpath = "/dev/${part}";

            $found = $partpath if $mounted->{$partpath};
        },
    );

    return $found;
}

# Currently only supports GPT-partitioned disks.
sub change_parttype {
    my ($partpath, $parttype) = @_;

    my $err = "unable to change partition type for $partpath";

    my $partnum = get_partnum($partpath);
    my $blockdev = get_blockdev($partpath);
    my $dev = strip_dev($blockdev);

    my $info = get_disks($dev, 1);
    die "$err - unable to get disk info for '$blockdev'\n" if !defined($info->{$dev});
    die "$err - disk '$blockdev' is not GPT partitioned\n" if !$info->{$dev}->{gpt};

    run_command(['sgdisk', "-t${partnum}:${parttype}", $blockdev], errmsg => $err);
}

# Wipes all labels and the first 200 MiB of a disk/partition (or the whole if it is smaller).
# If called with a partition, also sets the partition type to 0x83 'Linux filesystem'.
# Expected to be called with a result of verify_blockdev_path().
sub wipe_blockdev {
    my ($devpath) = @_;

    my $devname = basename($devpath);
    my $dev_size = PVE::Tools::file_get_contents("/sys/class/block/$devname/size");

    ($dev_size) = $dev_size =~ m|(\d+)|; # untaint $dev_size
    die "Couldn't get the size of the device $devname\n" if !defined($dev_size);

    my $size = ($dev_size * 512 / 1024 / 1024);
    my $count = ($size < 200) ? $size : 200;

    my $to_wipe = [];
    dir_glob_foreach(
        "/sys/class/block/${devname}",
        "${devname}.+",
        sub {
            my ($part) = @_;
            push $to_wipe->@*, "/dev/${part}" if -b "/dev/${part}";
        },
    );

    if (scalar($to_wipe->@*) > 0) {
        print "found child partitions to wipe: " . join(', ', $to_wipe->@*) . "\n";
    }
    push $to_wipe->@*, $devpath; # put actual device last

    print "wiping block device ${devpath}\n";

    run_command(['wipefs', '--all', $to_wipe->@*], errmsg => "error wiping '${devpath}'");

    run_command(
        ['dd', 'if=/dev/zero', "of=${devpath}", 'bs=1M', 'conv=fdatasync', "count=${count}"],
        errmsg => "error wiping '${devpath}'",
    );

    if (is_partition($devpath)) {
        eval { change_parttype($devpath, '8300'); };
        warn $@ if $@;
    }
}

# FIXME: Remove once we depend on systemd >= v249.
# Work around udev bug https://github.com/systemd/systemd/issues/18525 ensuring database is updated.
sub udevadm_trigger {
    my @devs = @_;

    return if scalar(@devs) == 0;

    eval { run_command(['udevadm', 'trigger', @devs]); };
    warn $@ if $@;
}

1;